The invention relates to a spark plug having a surface discharge gap. A spark plug with a surface discharge section for internal combustion engines is known, e.g. from the DE-OS 35 33 123, in which the insulation body is divided transversely and comprises an upper part on a connection side made of a material with a relatively low dielectric constant, and a lower part on a combustion chamber side made a material with a much higher dielectric constant. Such spark plugs are unobjectionable with respect to operation, but are relatively complicated to produce because of the divided insulator body.